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Finding the Fourth Proportional to 820.30, 1,230.72 and 491.18

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Solution

The fourth proportional to 820.30, 1,230.72 and 491.18 is: 736.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.30 : 1,230.72 = 491.18 : x
  2. Step 2: Convert to fraction form
    820.30/1,230.72 = 491.18/x
  3. Step 3: Cross multiply
    820.30x = 1,230.72 × 491.18
  4. Step 4: Simplify right side
    820.30x = 604,505.05
  5. Step 5: Solve for x
    x = 604,505.05/820.30
  6. Step 6: Final answer
    x = 736.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.